1 Land contracts or contracts for deed are a security agreement between a seller, called a Vendor, and a buyer, called a Vendee.  The Vendor agrees to sell a property by financing the purchase for the Vendee.
The two DNA strands are held together by interchain hydrogen bonds. H-bonds pair the bases in one chain to the complementary bases in the other chain. (A/T and G/C).
What enzyme unwinds DNA? A: The powerful enzyme DNA helicase unwinds the double strands of DNA by breaking the bonds between each of the complementary bases. These bases are held together by strong hydrogen bonds, but in breaking these, DNA helicase creates two single-stranded DNA molecules. Continue Reading.